Since 1910, the Smithsonian's National Museum of Natural History has inspired curiosity and learning about the natural world and our place in it.

July 2014

07/24/2014

Picture a snail that’s so tiny, it could disappear behind a kernel of corn.

Such small creatures can easily be overlooked-- but if you value having access to fresh, clean drinking water, then you should pay attention to this one.

Behold, the springsnail:

A live springsnail (Pyrgulopsis robusta) found in Snake River, Idaho. (Courtesy of Robert Hershler, Smithsonian Institution)

Springsnails belong to a group of invertebrates that grow to be less than 1/4 inch high, and are one of the most diverse types of aquatic animals native to North America. Scientists believe that these snails play an important role in freshwater ecosystems, keeping them clean by eating algae and serving as food for fish and other critters. More than 130 different kinds of springsnails live west of the Mississippi River alone, thriving in and around the same freshwater springs that humans depend on for drinking water, livestock grazing and recreation.

Over the past few decades, groundwater pumping and depletion in the western United States has greatly accelerated due to an increase in human demand and global climate change. The result: a large number of dried springs scattered throughout the West, water shortages for people living in these areas and major declines in springsnail populations. Scientists now consider the springsnail to be the poster child for imperiled ecosystems that are reliant on freshwater springs.

How does the fate of this snail affect you? To put it simply, save the springsnail and your groundwater is also saved.

A dried spring at Las Palomas, Mexico, formerly occupied by the now extinct Pyrgulopsis brandi, a species of springsnail. The spring dried out as a result of groundwater pumping. (Courtesy of James J. Landye)

The Smithsonian is playing a leading role in the fight to conserve the springsnail. A new study published online in Bioscience(July 16) by National Museum of Natural History scientist Robert Hershler reports that springsnails have become the focus of new conservation activities over the past few decades during which various species have started to disappear.

Most springsnail species have narrow ranges, often consisting of a single spring or system. If the spring dries up or becomes polluted from activities such as cattle grazing, these snails cannot survive. Invasive species in freshwater areas are also taking a toll on springsnail populations. At least five springsnail species have gone extinct since the early 1900s and 80% of living species are listed as endangered by the American Fisheries Society.

The good news is that during the past 25 years, considerable strides have been made in providing protection for springsnails and the fresh groundwater sources they call home. Scientists are beginning to understand how springsnail populations have changed over time, both from human activities, and, on longer time scales, from climate change. Museum collections provide important baselines for these studies-- the Smithsonian stewards over a million springsnail specimens that represent more than 100 different species collected since the 1980s.

While Hershler’s research is an important step towards better understanding these small snails, more foundational work needs to be done. His paper calls for additional research on the biology of the springsnail and links to a driving force behind conservation efforts in the western United States today—the need for fresh groundwater shared by humans and snails alike.

By Kathryn Sabella, Press Officer, Smithsonian's National Museum of Natural History

07/18/2014

California’s Channel Islands hug the coast from Santa Barbara to San Diego, but have never been attached to the mainland. This makes them an ideal setting for evolutionary biologists and archaeologists alike to understand how humans have shaped biodiversity across millennia. Credit: Torben Rick, Smithsonian Institution.

The Setting: California’s Channel Islands, otherwise known as “The Galapagos of North America.” Home to more than 270 species that only exist there.

The Conundrum: You’re a land manager trying to restore the damaged archipelago to its natural state. Sounds straightforward, but if humans have been altering the island ecosystems for roughly 13,000 years it quickly becomes a philosophical challenge. When, exactly, were the Channel Islands natural?

To complicate things, you need to plan for the possible effects of climate change: rising sea levels, changing precipitation patterns, and rising temperatures. Which species are going to be resilient enough to survive these pressures?

Enter: an interdisciplinary team of researchers led by archaeologist Torben Rick and ornithologist T. Scott Sillett, both with the Smithsonian Institution, and The Nature Conservancy’s Scott Morrison. In a new study published in BioScience, plant and animal experts, along with ecologists, geneticists, archaeologists, paleobiologists, and geologists trace 20,000 years of the California archipelago’s history.

Their investigations show island ecosystems and biodiversity in flux across millennia, with sea level, climate, and humans—first Native Americans, then ranchers, and now tourists and land managers—affecting which species survive and adapt and which ones fail.

The loggerhead shrike thrived when ranches and grass blanketed the Channel Islands. Now that the cattle and other grazers are gone, land managers will have to decide whether or not to protect the bird’s open habitat or let woody plants take hold. Credit: Lyndal Laughrin, UC Natural Reserve System.

The Solution: The scientists don’t tell us which period in history to use as a benchmark for the Channel Islands’ restoration. And they don’t tell us which plants and animals to protect. That’s not their job. Instead, they make it clear that some decisions will involve difficult tradeoffs. Save one bird’s grassland habitat, and woody plants might suffer.

Ultimately the authors suggest taking the long view to understand which species may be best adapted to the environment, as it is now and as we think it will be in the future. This particular study is done, but the Channel Islands experiment will continue.

Scientists don’t yet know how the island fox got to the California archipelago, but it arrived during the human era, sometime before 7,000 years ago. After being listed as endangered in the 1990s, their populations have rebounded due to active management. Credit: Torben Rick, Smithsonian Institution.

Editor’s note: This study is the result of a collaboration between the Smithsonian Institution, The Nature Conservancy, the U.S. National Park Service, and a host of additional partners, including museums, universities, governmental agencies, and non-profit organizations.

07/14/2014

The Insect Zoo is excited to announce that tarantula feedings will now happen every day of the week! Our three new Monday tarantulas have made their debut, but we need your help to name them. Meet our new stars below, and then vote for your favorite names on our Facebook page.

Mexican Fireleg Tarantula:

True to its name, the Mexican Fireleg tarantula (Brachypelma boehmei) is native to Mexico. Firelegs prefer dry scrubland areas, where they live in self-made or adopted burrows. Males are exceptionally long lived for tarantulas, reaching maturity after 7 or 8 years, and females can live to be 20. Our Fireleg still has some growing to do until it reaches full size, so we still don’t know if it’s a boy or girl! Do you think (s)he is a Lava, Pyro, or Flash?

Bolivian Salmon Tarantula:

Native to Bolivia and Argentina, Bolivian Salmon Pink tarantulas (Acanthoscurria chacoana) are relatively large, growing to 7 or 8 inches in legspan. Covered in black-brown hair, they also have long pink hairs on their legs and abdomen. Aside from their wonderful fashion sense, these urticating hairs can be kicked off the abdomen as a defense, irritating skin and soft tissues. Would you say our tarantula’s an Urti, Webster, or Flash?

Brazilian Whiteknee Tarantula:

Fast growing and good eaters, Brazilian Whiteknee Tarantulas (Acanthoscurria geniculata) reach maturity in as little as three or four years. Native to the forests of Brazil, these tarantulas are terrestrial, hiding out under leaves and logs. With its flashy black and white striped legs, is Stripes, Rio, or Pouncer a good fit?

Go vote for your favorite names! The winning names will be announced on Monday, July 21.

07/11/2014

That’s the main message of a new paper published in Science by the Director of the Smithsonian’s Human Origins Program, Rick Potts, and his colleagues Susan Antón, Professor of Anthropology at New York University, and Leslie Aiello, President of the Wenner-Gren Foundation for Anthropological Research.

The traditional “savanna hypothesis” postulates that many of the adaptations that distinguish our genus, Homo – such as walking upright, making tools, a large brain and body size, and a long period of maturation – were associated with cooler, drier habitats and the spread of grasslands. But this new study fine-tunes the timing of these traits to reveal a much more piecemeal process rather than a package deal. The climate framework they present, based on Earth’s astronomical cycles, demonstrates that these characteristic emerged against a backdrop of fluctuating climate that included both wetter and drier times of varying intensity.

It’s also clear that human evolution did not proceed in a linear fashion, with one species evolving after another. Soon after our genus (Homo) first evolved, by about 2.4-2.3 million years ago, there were at least three different species of Homo walking the earth: Homohabilis, Homorudolfensis, and slightly later Homo erectus. In fact, these species overlapped in time with each other and even with Australopithecus and Paranthropus, two other genera of early humans. Some of their fossils have even been found at the same prehistoric sites. Anatomical traits and behaviors were mixed and matched, with some more human-like features found in some species, and others in different species, which according to the authors indicates that each species utilized a different strategy to survive. This diversity has since dwindled due to the extinction of all other human species aside from our own. We are the last biped standing, but currently stand at over 7 billion strong. Potts attributes our great evolutionary success to our adaptive versatility: the ability of the earliest members of our genus to innovate – to find new foods, make new tools, exploit new habitats, and eventually migrate out of Africa – in the face of ever-changing conditions.

This chart depicts hominin evolution from 3.0-1.5 million years ago and reflects the diversity of early human species and behaviors that were critical to how early Homo adapted to variable habitats, a trait that allows people today to occupy diverse habitats around the world. Image courtesy of Antón, Potts and Aiello (2014), Science 345(6192).

By Dr. Briana Pobiner, Human Origins Program, Smithsonian's National Museum of Natural History

07/01/2014

The World Cup is the perfect time to talk about the natural history of hummingbirds.

We have one person to thank for this: Dr. Richard Zusi, the Smithsonian’s emeritus curator of birds and the grandfather of Team USA midfielder Graham Zusi.

A hummingbird’s heart rate can soar to more than 1,200 beats a minute when flying. During a game, a soccer player’s will hover around 172 beats per minute. Image: Thalurania colombica, by Flickr user Kathy & sam under Creative Commons.

Dr. Zusi remains one of the all-time greatest comparative anatomists in ornithology. He has written entire books describing the insides of these hovering creatures. In one, he methodically documented 132 different muscles within the hummingbird—from its eyes to its weak hindlimbs.

Smithsonian emeritus curator of birds, Dr. Richard Zusi.

Zusi’s studies have informed a larger understanding of variation, adaptation, and evolution among hummingbirds. No they were not around when the dinosaurs roamed, but they have graced planet Earth for some 35 million years.

Today there are around 330 different species of hummingbirds. While they can and do eat insects for protein, they are widely celebrated for their role as pollinators. Some plants, like Heliconia caribaea, even depend on hummingbirds to survive.

Although he retired 20 years ago, Dr. Zusi continues to publish. We interrupted his unpaid research to ask him to ruminate on soccer and hummingbirds. He emailed these thoughts:

Hummers use their feet only for sitting and scratching their heads.

Soccer players use their feet for everything except scratching their heads.

Hummers sometimes fly backwards.

Soccer players sometimes run backwards.

Hummers are aggressive and fight other hummingbirds.

Soccer players are aggressive and fight other soccer players.

Hummers protect their food flowers from other hummers, not always successfully.

Soccer players protect their net from other teams, not always successfully.

Hummingbirds prosper by laying only two eggs.

Soccer games often prosper with only two goals.

Dr. Zusi has a dry sense of humor. His protégé and successor Dr. Gary Graves said Zusi had him laughing non-stop when the two participated in a 1986 expedition to Brazil. They were part of a team documenting the fauna of the Rio Xingu, a tributary of the Amazon. During a span of 7 weeks, they ate armadillo soup, bathed with piranhas, and found more than 260 species of birds, including the spectacular hummer Lophornis gouldii .

Smithsonian bird curator, Dr. Gary Graves, holds two of the larger specimens from our collection of approximately 12,000 hummingbirds. For the past 150 years, scientists like Graves and his predecessor, Dr. Richard Zusi, have assembled and shared the research collection with scientists worldwide.

These bird specimens now reside in the collections of the Museum of Zoology at the University of Sao Paulo and the Smithsonian’s National Museum of Natural History. Our curators and collection managers will preserve them in perpetuity for future researchers to study.

Graham Zusi, if you’re too busy to see this collection while you’re in Brazil, come visit us in Washington, D.C. Also, your Grandfather and Grandmother Zusi are proud of you. Good luck!

WANT MORE?

If you think scoring soccer players are impressive in slow motion, watch this high-speed video of flying hummingbirds shot by engineering students from Stanford University.